Sharif ul-Hashim, whose full name was Sayyid Abu Bakr Abirin al-Hashimi, was a Sufi scholar and missionary of Sayyid descent through the Ba-Alawi lineage of Hadhramaut (Yemen), who came to Sulu from Johor. Settling in Buansa in the first half of the 15th century, he spent about thirty years spreading Islam in the region, promulgated the first Sulu code of laws (the Quran-based 'Diwan'), and established Islamic political institutions, founding the Sultanate of Sulu. He is thus one of the pivotal figures of Southeast Asian Islamic history. His tomb is traditionally said to lie on a slope of the sacred Mount Tumantangis (Bud Tumantangis) in Indanan, Sulu; the exact location is disputed.